【作者】 王琪；

【导师】 高锦明；

【作者基本信息】 西北农林科技大学 ， 植物学， 2007， 硕士

【摘要】 植物内生真菌（endophytic fungi）是指在健康植物寄主的各种组织和器官内部或细胞间隙中度过全部或近乎全部生活周期而不使寄主表现任何症状的一类真菌。作者于2005年6月至2006年12月对苦楝（Melia azedarach L.）中内生真菌进行了初步的研究,取得了以下结果:从苦楝（Melia azedarach L.）的根、茎、叶、果实中分离得到99株14个属的内生真菌（33株因不产孢子未鉴定）。其中7月分离得到7个属,10月得到14个属的内生真菌。由分离结果可知,根、茎中内生真菌的属多于叶和果实,且曲霉属的灰绿曲霉组、链格孢属和未见孢子Ⅰ在全株均有分布。以小麦赤霉病菌、番茄灰霉病菌、辣椒疫霉病菌、苹果炭疽病菌、棉花枯萎病菌为供试菌种,在50mg/mL的浓度下,采用抑制菌丝生长速率法和抑制孢子萌发法对99株内生真菌发酵产物进行了杀菌活性筛选,发现O-L-1、O-L-2、O-L-5、O-RC-3这四个菌株的发酵液和菌丝体粗提物对这些病原菌具有不同程度的抑制菌丝生长活性作用,其菌丝体粗提物对番茄灰霉菌、棉花枯萎菌有明显的抑制孢子萌发作用。对各菌株次生代谢物进行检测,可知O-L-5、O-SCⅡ-4和O-RC-3能产生较多的苦楝素,最终确定O-L-5和O-RC-3为目的菌株。对O-L-5大量发酵,从其发酵产物中分离得到四个化合物M1-M4,经GC-MS、¹HNMR、¹³CNMR)等波谱鉴定,并与标准品、文献值以及图谱库对照,鉴定分别为麦角甾醇过氧化物、4,6,8（14）,22（23）-四烯-3-酮麦角甾烷、M3未知,7-methyl-8-hydroxy-2- acetyl-furanonaphthoquinone。其发酵产物中有大量的油状物,对其进行GC-MS分析可知,为16和18碳的高级脂肪酸。更多还原

【Abstract】 Plant endophytic fungus is a kind of fungus which spends all or most life cycles in plant posts, and does not make any diseased symptom. The primary studies on metabolites of endophytic fungus in Melia azedarach have been carried out from July, 2005 to December,2006. The results are as follow:Ninety-nine isolates of endophytic fungi belong to 14 genus, besides 33 unknown, were isolated and identified from the roots, stems, leaves and fruits of Melia azedarach L, 7 genera in July and 14 genera in October. And the results showed that the number of genus in root and stem is more than leaf and fruit, moreover, A. glaucus、Alternaria and the no sporeⅠexist in the whole plant.The fungi cidal activities of their fermentation products were examined. By means of mycelium growthrate, the acetone extracts of mycelium of O-L-1,O-L-2,O-L-5 and O-RC-3 strains had a certain degree fungi cidical activity against Fusarium graminearum, Botrytis cinerea, Phytophtho ra capsici, Glomerella cingulata, Fusarium oxysparum f.sp. vasin fectum at the concentration of 50mg/mL,and exhibited moderate activity against Botrytis cinerea, Fusarium oxysparum f.sp. vasin fectum in the test of spore germination.Toosendanin of metabolic products of the strains have been analysed. It was shown that the fungus O-L-5,O-SCⅡ-4 and O-RC-3 are the goal.And the final goal are O-L-5 and O-RC-3.Ferment O-L-5 for 50L, from the fermentation products, 4 compounds were separated. They are ergosterol peroxide;4,6,8（14）,22（23）-tetraen-3-one-ergostane;7-methyl-8- hydroxy -2-acetyl-furanonaphthoquinone and one unknown, identified by EI-MS, ¹HNMR, ¹³CNMR and compared with the references,standard compounds are also used to test.In the fermentation products, there are much of oil.By GC-MS analyse, we know that it is composed of higher aliphatic acid of 16 and 18 carbons.更多还原